Linear organopolysiloxanes modified by mesogenic groups are known and described for example, by H. Finkelmann, G. Rehage, Makromol. Chem., Rapid Commun., 1, 733 (1980), H. Ringsdorf, A. Schneller, Makromol. Chem., Rapid Commun., 3,557 (1982), G. W. Gray, D. Lacey, G. Nestor, M. S. White, Makromol. Chem., Rapid Commun., 7, 71 (1986), H. J. Coles, R. Simon, Mol. Cryst. Liq. Cryst., 102, 75 (1984), R. M. Richardson, N. J. Herring, Mol. Cryst. Liq. Cryst., 123, 143 (1985), H. Richard, M. Mauzac, H. T. Nguyen, G. Sigaud, M. F. Archard, F. Harduin, H. Gasparoux, Mol. Cryst. Liq. Cryst., 155, 141 (1988), H. Sackmann, H. Schubert, Z. Chem., 26, 66 (1986), V. P. Shibaev, N. A. Plate, Advances in Polymer Sciences, Springer Verlag, 60-61, 173 (1984), H. Zaschke, M. Krucke, M. Schlossarek, Acta Polymerica, 39, 607 (1988) and U.S. Pat. No. 4,358,391 (H. Finkelmann, Wacker-Chemie GmbH; published on 9th November 1982).
With these organopolysiloxanes, conversion into the liquid crystal orientated state often presents difficulties because relatively long conditioning times are required in order to achieve a high degree of order. Although shorter-chain species of the type mentioned above orientate themselves spontaneously, they usually have undesirable tacky properties.
Furthermore, U.S. Pat. No. 4,410,570 (F.-H. Kreuzer, Consortium fur elektrochemische Industrie GmbH; published on 18th October 1983) describes cyclic organopolysiloxanes having at least one mesogenic group and European Published Specification 163,495 (To Imai, Toray Silicone Co. Ltd., published on 4th December 1985) describes non-crosslinked branched organopolysiloxanes having at least one mesogenic radical.
It is therefore an object of the present invention to provide organosilsesquioxanes having at least one mesogenic side group. Another object of the present invention is to provide a process for preparing organosilsesquioxanes having at least one mesogenic side group. Another object of the present invention is to provide organosilsesquioxanes containing a large number of mesogenic groups which have a wide variation in properties. A further object of the present invention is to provide organosilsesquioxanes having at least one mesogenic side group which have relatively high glass transition points. A still further object of the present invention is to provide organosilsesquioxanes having at least one mesogenic side group which are capable of being crosslinked.